Field of the Invention
The present invention relates to an organic light emitting display device, and more particularly to an in-cell type touch panel integrated flexible organic light emitting display device.
Description of the Related Art
The field of display devices for visually displaying electrical information signals has grown rapidly. Thus, studies for developing performance such as thinning, weight lightening, and low power consumption, of various display devices have continued. Representative examples of the display devices include a Liquid Crystal Display (LCD) device, a Plasma Display Panel (PDP) device, a Field Emission Display (FED) device, an Electro-Wetting Display (EWD) device, an Organic Light Emitting Display (OLED) device, and the like.
In particular, the organic light emitting display device is a self-light emitting display device that does not need an additional light source unlike a liquid crystal display. Thus, the organic light emitting display device can be manufactured into a lightweight and thin form. Further, the organic light emitting display device is advantageous in terms of power consumption since it is driven with a low voltage. Also, the organic light emitting display device has a fast response speed, a wide viewing angle, and an infinite contrast ratio. Therefore, the organic light emitting display device has been recognized as a next-generation display device. However, in spite of such advantages, the organic light emitting display device has a disadvantage of being particularly vulnerable to moisture and oxygen. Thus, there is a problem in obtaining the reliability as compared with the other display devices.
The organic light emitting display device displays images using an organic light emitting element as a self-light emitting element. The organic light emitting display device includes a plurality of pixels formed of organic light emitting elements. The organic light emitting element includes a first electrode (e.g., anode), an organic light emission layer, a second electrode (e.g., cathode), and a bank. The organic light emission layer formed of an organic substance and configured to generate electro luminescence on the basis of an electrical signal applied between the first electrode and the second electrode is disposed between the first electrode and the second electrode. A plurality of organic light emitting elements is separated by the bank.
If the organic light emitting display device is of a top-emission type, the first electrode has reflective characteristics and the second electrode has transparent characteristics or translucent characteristics in order to emit a light emitted from the organic light emission layer in an upward direction. Further, in order to secure the reliability, a transparent encapsulation part configured to protect the organic light emitting element against oxygen and moisture is formed on the organic light emitting element.
Such an organic light emitting display device may further include a touch panel (or other type of touch user interface). Generally, a touch panel includes an add-on type touch panel attached to an external surface of an organic light emitting display device, an on-cell type touch panel disposed on an organic light emitting display device, and an in-cell type touch panel integrated within an organic light emitting display device. In the in-cell type touch panel integrated organic light emitting display device, a touch panel is integrated. Thus, it can be realized in a thin form as compared with the add-on type or on-cell type organic light emitting display device.
In recent years, a flexible organic light emitting display device (F-OLED) capable of maintaining a display performance even if bent like paper has been developed. It is to be substituted for nonflexible display devices using a flexible substrate formed of a flexible material, such as plastic, metal or a flexible glass. Such a flexible substrate is applied to a display device that has an excellent durability and the substrate cannot be easily broken. Meanwhile, various technologies for integrating a touch panel in such display devices have been under research. In particular, if overall thickness of a display device is increased due to an attached touch panel, the flexibility of a flexible organic light emitting display device is decreased. Therefore, technologies capable of realizing an excellent touch performance while minimizing an increase in thickness are needed.